18th c. "jam" in a new sense?

[Dale Coye]

I found this description in a local town history.  Apart from it being a 
sense of the word that I didn't find in either the OED online or DARE, note the 
delight the author takes in the concept of 5000 trees coming down at once.

Dale Coye
Wilton, NH

>From Historical Sketches of Wilton New Hampshire 1739-1939, Hamilton S. 
Putnam, ed.  The Wilton Historical Society, 1939
 
JAM  pp. 9-10    Because of the dense forests, settlers were forced to cut 
down thousands of these big trees to make room for public buildings, houses, 
bridges and roads.  It was customary to cut down trees and burn them.  Sometimes 
the early citizens held a “jam.”  All the trees on a certain tract would be 
cut nearly off, then, when all was ready the jam would be started by felling 
one big tree.  The giant timber crashing against others would send the whole 
tract smashing to the ground, with a fearful crash, filling the air with broken 
limbs and shaking the ground for a long distance.
            This method of clearing land eliminated a great deal of chopping 
and was supposed to prevent the lodging of trees. It was a magnificent sight 
to see from one thousand to five thousand of these original “giants of the 
forest” go down at once.  But it was a dangerous business, as a premature fall or 
high wind might start the “jam” before the workmen were ready.  In spite of 
all manner of precautions several of the early settlers were killed by these 
falling trees.
            The trees were left on the ground to dry for several months.  
After selected logs had been removed from the fallen timber area the whole 
section was set on fire.  Dry timber, leaves, and dry mould of centuries burned like 
tinder and within a few minutes the heat from the blazing pile was like that 
of a “blazing oven.”  Great precautions had to be taken to prevent the 
frightful force and fury of the fire from burning beyond the bounds and a strong 
force of men was needed.